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Indoor/Outdoor Power readings!

hopper1hopper1 Posts: 4,708
edited February 2010 in Training, fitness and health
A little while back there was a post regarding power output on a turbo being less than that on the road.
Main reasons given, IIRC, were due to heat build up indoors.

Well, my indoor power output is around 12-15 watts (Av.) greater than my output on the road!
Any ideas? Sensible offerings please. :wink:
Start with a budget, finish with a mortgage!
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  • AnonymousAnonymous Posts: 28,799
    Not a clue!

    I'm as much as 20% down on the turbo!

    Do you zero it at the start of every ride?
  • BhimaBhima Posts: 2,145
    hopper1 wrote:
    12-15 watts (Av.) greater

    Been getting coaching from NapD?
  • hopper1hopper1 Posts: 4,708
    NapoleonD wrote:
    Not a clue!

    I'm as much as 20% down on the turbo!

    Do you zero it at the start of every ride?

    Yep... Zero immediately after every download, so I don't forget!
    Start with a budget, finish with a mortgage!
  • AnonymousAnonymous Posts: 28,799
    That is absolutely bizarre :shock:
  • BhimaBhima Posts: 2,145
    What sort of testing are you doing?
  • hopper1hopper1 Posts: 4,708
    Bhima wrote:
    What sort of testing are you doing?

    :?:
    Start with a budget, finish with a mortgage!
  • AnonymousAnonymous Posts: 28,799
    Is it a wireless PT? The only explanation I can come up with is, if it is wireless, interference from wifi or electrical items or similar. If it's wired then I'm stumped.
  • nmcgannnmcgann Posts: 1,780
    hopper1 wrote:
    A little while back there was a post regarding power output on a turbo being less than that on the road.
    Main reasons given, IIRC, were due to heat build up indoors.

    Well, my indoor power output is around 12-15 watts (Av.) greater than my output on the road!
    Any ideas? Sensible offerings please. :wink:

    Dunno why, but I'm the same - better power output on the turbo than road. My own theory is that it's something to do with constant resistance loads. Road riding is never like that, the resistance changes all the time.

    BTW, I don't know if there's a correlation, but my peak power is very low and I have no sprint at all.
    --
    "Because the cycling is pain. The cycling is soul crushing pain."
  • hopper1hopper1 Posts: 4,708
    NapoleonD wrote:
    Is it a wireless PT? The only explanation I can come up with is, if it is wireless, interference from wifi or electrical items or similar. If it's wired then I'm stumped.

    You're stumped then chap :shock: :wink:
    Maybe it will change next month, when the new SL+ arrives. :roll:
    Start with a budget, finish with a mortgage!
  • AnonymousAnonymous Posts: 28,799
    It's not as though it's a small discrepancy either :shock:

    My peak on the road at the moment is ~1240, on the turbo it's ~1020. That is easily explainable though.
  • jibberjimjibberjim Posts: 2,810
    hopper1 wrote:
    Well, my indoor power output is around 12-15 watts (Av.) greater than my output on the road!
    Any ideas? Sensible offerings please. :wink:

    You're more specificly fit at riding the very limited torque range that riding on a trainer forces you to do. Unlike the road where the resistence changes all time - slight changes in road surface, wind, gradient etc. mean to maintain constant power you have to adjust the forces you put out.

    I suspect you've spent a lot of time on the trainer doing steady power outputs?
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • APIIIAPIII Posts: 2,010
    Are you talking about a 20 minute test or an hour's normalized power?
  • hopper1hopper1 Posts: 4,708
    jibberjim wrote:
    hopper1 wrote:
    Well, my indoor power output is around 12-15 watts (Av.) greater than my output on the road!
    Any ideas? Sensible offerings please. :wink:

    You're more specificly fit at riding the very limited torque range that riding on a trainer forces you to do. Unlike the road where the resistence changes all time - slight changes in road surface, wind, gradient etc. mean to maintain constant power you have to adjust the forces you put out.

    I suspect you've spent a lot of time on the trainer doing steady power outputs?

    Good point, Jim.
    Because of work commitments, I do spend more time on the turbo, or gym bikes, and that has mainly been at one pace.
    I've just started doing intervals again, on both road and turbo, in a bid to stop being a one speed rider!
    Hopefully this will sort out the power output difference, too.
    Start with a budget, finish with a mortgage!
  • doyler78doyler78 Posts: 1,951
    You are comparing like for like ie 20 min intervals versus 20 min intervals?

    Is the VI close to 1.0 outside?

    Perhaps your efforts are underpowered because they aren't properly paced outdoors ie your power output is too inconsistent to give you a valid number for comparison.

    How do the efforts feel in terms of perceived effort between indoor workouts and outdoor workouts? Perhaps you are one of the few that can really motivate themselves indoors but lose focus outdoors.
  • hopper1hopper1 Posts: 4,708
    doyler78 wrote:
    You are comparing like for like ie 20 min intervals versus 20 min intervals?

    Is the VI close to 1.0 outside?

    Perhaps your efforts are underpowered because they aren't properly paced outdoors ie your power output is too inconsistent to give you a valid number for comparison.

    How do the efforts feel in terms of perceived effort between indoor workouts and outdoor workouts? Perhaps you are one of the few that can really motivate themselves indoors but lose focus outdoors.

    1. Yes. But using a one hour at tempo.
    2. Yes.
    3. Possible, I do tend to 'mind wander' a bit, out on the road.
    4. Perceived effort is higher indoors. I do seem to be able to motivate well, when on the turbo.

    Next month I'll have a new, wireless powertap to pair with my 705. I'm kind of hoping that I'll be able to use the 'virtual partner' to give me a pace target and improve my outdoor training.

    Thanks... :wink:
    Start with a budget, finish with a mortgage!
  • chrisw12chrisw12 Posts: 1,246
    I've got a feeling that my turbo power is higher indoors as well, but I'm not 100% sure as there's a lot of variables flying around and two different powertaps.

    When the snow started I went indoors for most of my training and after a slow start my power figures soon started going higher than my old outdoor figures. I thought great this is working, fitness is improving. Then snow stopped, I went outdoors done some unofficial tests and :cry:

    I've had two weeks outdoors now, back indoors today and it seems figures are up again. :D

    Now reasons why,FOR ME

    1) My pacing on the road is terrible, I have a habit of trying to set 4 min pbs in the first four mins of any duration I'm riding. :evil: I just don't do this on the turbo, in fact I normally do the opposite.

    2) Very tight cadence and torque band on the turbo (as Jim said). The golden cheetah with quadrant analysis highlighted this big difference for me. Suggest you have a look if you can.

    3) Position difference. On the turbo I sit up, on the road I'm in tri bars.


    So lessons FOR ME. Turbo is great, very controlled and good for motivation, it's nice to see bigger figures but it will not replace road riding for that all important specificity. I also need to have a big look at pacing and perhaps do some experimenting with some negative split pacing plans.
  • PokerfacePokerface Posts: 8,640
    I find it hard sometimes to get good power numbers on the road - because unless the road is going slightly uphill - I can;t pedal fast or hard enough to generate good power numbers!

    On a turbo - you set the resistance and away you go and just focus on hitting your numbers.


    On the road - due to changing terrain, etc- sometimes you can be going fast - but putting out very little power, so it's harder to get good numbers.

    When I want to do real power testing on the road - I always use the same stretch of uphill road (20 minutes worth) to do my tests. Forces me to put out constant power and work hard.


    Otherwise my road numbers would also be less than my turbo numbers.
  • Pokerface wrote:


    On the road - due to changing terrain, etc- sometimes you can be going fast - but putting out very little power, so it's harder to get good numbers.

    I think that's the main thing. Trying to do 3x20s on a turbo and maintain a constant hr/output is much easier than on the road, basically because there's no where in the North East that's flat or wind free.

    @Chris: I had the opposite experience to you with being stuck indoors on the turbo. Did plenty of 3x20 threshold sessions, 1min on 1min off intervals (plus a few gym sessions) and I'm absolutely flying at the moment, on the flat at least. Just need to work on the climbing/endurance and everything should fall into place. All in all I'm stronger, leaner and a lot fresher than I was last winter, and I've ridden by bike a handful of times outside of my garage since before Christmas. I have friends though who really find it difficult to transfer their turbo improvements on to the road.
    "A cyclist has nothing to lose but his chain"

    PTP Runner Up 2015
  • hopper1 wrote:
    NapoleonD wrote:
    Not a clue!

    I'm as much as 20% down on the turbo!

    Do you zero it at the start of every ride?

    Yep... Zero immediately after every download, so I don't forget!
    You should zero the torque on your power meter before your ride, not after.
  • hopper1hopper1 Posts: 4,708
    hopper1 wrote:
    NapoleonD wrote:
    Not a clue!

    I'm as much as 20% down on the turbo!

    Do you zero it at the start of every ride?

    Yep... Zero immediately after every download, so I don't forget!
    You should zero the torque on your power meter before your ride, not after.

    Alex, surely it's the same thing?... I zero after I've finished downloading and it isn't touched again until I get on my bike again...
    Unless I'm missing something, it's the same both ways. :?
    Start with a budget, finish with a mortgage!
  • jibberjimjibberjim Posts: 2,810
    hopper1 wrote:
    Alex, surely it's the same thing?... I zero after I've finished downloading and it isn't touched again until I get on my bike again...
    Unless I'm missing something, it's the same both ways. :?

    You're assuming the things that can make it go out of calibration only happen when you're using the bike. This isn't the case, although certainly you'll have less variance than if you ignored it altogther. Also remember temperature has a big impact on some power reading devices.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • hopper1hopper1 Posts: 4,708
    Ok, guys... I'll zero the Powertap directly before I start my rides.
    I wasn't thinking of any other outside interferences.

    Oh... When you say 'zero', you're referring to 'clearing' the powertap:
    <clr> ?
    Start with a budget, finish with a mortgage!
  • AnonymousAnonymous Posts: 28,799
    hopper1 wrote:
    Ok, guys... I'll zero the Powertap directly before I start my rides.
    I wasn't thinking of any other outside interferences.

    Oh... When you say 'zero', you're referring to 'clearing' the powertap:
    <clr> ?

    No, you need to zero the torque at the start of every ride otherwise all your readings can be meaningless. I fell foul of this last year when I forgot to do it and all my readings were high although I didn't realise till much later.
    After you have cleared it, start pedalling, move the pointer to the watts line and ensure it's displaying current watts. Stop pedalling so the rear is coasting then hold down the select button untill the 'watts' starts flashing. Wait until this says zero (ensure the rear is still coasting without any pressure on the pedals) then press the select button again.

    You have to do it at the start of every ride!!

    I do it by holding the back wheel up, spin the pedals a couple of times with my hands then zero it, that way I ensure there is no pressure on the pedals...
  • EdwinEdwin Posts: 785
    @ShockedSoShocked - 3x20's ? (!!!!)

    2x20's are bad enough, that sounds horrendous.
  • hopper1 wrote:
    Ok, guys... I'll zero the Powertap directly before I start my rides.
    I wasn't thinking of any other outside interferences.

    Oh... When you say 'zero', you're referring to 'clearing' the powertap:
    <clr> ?

    What do you need to do if you are using a 705 with the Powertap?
  • Edwin wrote:
    @ShockedSoShocked - 3x20's ? (!!!!)

    2x20's are bad enough, that sounds horrendous.

    Yeh, they're not the most fun i've had! My coach recommended them for threshold sessions, and since I wasn't riding on the road at all i was pretty fresh for each one. I have them pencilled in after a gym session usually, and it bloody hurts.
    "A cyclist has nothing to lose but his chain"

    PTP Runner Up 2015
  • jibberjimjibberjim Posts: 2,810
    lloydy75 wrote:
    What do you need to do if you are using a 705 with the Powertap?

    Wake the PT up.

    Go to Ant Settings and select CALIBRATE. wait for the calibration successful message to come back.
    Jibbering Sports Stuff: http://jibbering.com/sports/
  • jibberjim wrote:
    lloydy75 wrote:
    What do you need to do if you are using a 705 with the Powertap?

    Wake the PT up.

    Go to Ant Settings and select CALIBRATE. wait for the calibration successful message to come back.

    Thanks for that that's what I do, I thought I was missing something about the zeroing.
  • hopper1hopper1 Posts: 4,708
    NapoleonD wrote:
    No, you need to zero the torque at the start of every ride otherwise all your readings can be meaningless. I fell foul of this last year when I forgot to do it and all my readings were high although I didn't realise till much later.
    After you have cleared it, start pedalling, move the pointer to the watts line and ensure it's displaying current watts. Stop pedalling so the rear is coasting then hold down the select button untill the 'watts' starts flashing. Wait until this says zero (ensure the rear is still coasting without any pressure on the pedals) then press the select button again.

    You have to do it at the start of every ride!!

    I do it by holding the back wheel up, spin the pedals a couple of times with my hands then zero it, that way I ensure there is no pressure on the pedals...

    Ah, cheers NapD... I wasn't doing that :oops: Never saw anything about that in the destructions... :roll:
    Well, I'm about to go away to work, so I can't try out the 'zero'd' method... :evil:
    So, will now have to wait 2 weeks before I can check again.
    Then I'll have a wireless one to play with, and the 705!

    Thanks again, guys, much appreciated. :wink:
    Start with a budget, finish with a mortgage!
  • chrisw12chrisw12 Posts: 1,246
    Not so fast tiger.

    Calibration is slightly differeent depending on which model of powertap your are using iirc. There's a difference between wired and wireless modles. Best do some reading perhaps.

    I'm not so sure that the newer wireless ones need this calibration at the start of every ride. I do it mostly anyway, but when I haven't bothered I've SEEN no differences. Auto zero should pick up problems anyway unless the zeroing is way out. :?:
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